Abstract: On the basis of the MTS theoretical analysis and numerical test of the measured data,some problems on the enhancement of the effect of monitoring earthquake precursors through measurement of deep electrical variations by the MTS method is discussed. The obtained results show that of the several defined MT apparent resistivities,the still unused apparent resistivity,the real part of the impedance has some unique advantages and can possibly become a better parameter for monitoring the deep electrical variation as an earthquake precursor. It is necessary to select the parameters having highter relative precision as the main parameters to be monitored on the basis of the analysis of various effects on the MT response functions,which result from the error distribution in different channels,the error propagation and accumulation in the computation process. The synthetic judgement method with multi-parameters is the basic method to distinguish the deep electrical variations as an earthquake precursor. The above mentioned conclusion is justified by some observed MTS data reflecting earthquake precursors.